The carcinogenic activity of some 5-nitrofuran derivatives in the rat.

Three 5-nitrofuran derivatives showed carcinogenic activity when fed to female Holtzman rats at levels of 0.1 to 0.3% in a commercial diet for up to 44.5 weeks, while 2 other 5-nitrofuran derivatives and 5,5-diphenylhydantoin were inactive. Formic acid 2-[4-(5-nitro-2-furyl)-2-thiazolyl]hydrazide induced benign and malignant tumors of the mammary glands, adenomas or adenocarcinomas of the kidney, adenocarcinomas of the intestine, and carcinomas of the external auditory canal. 5-Nitro-2-furaldehyde semicarbazone produced only mammary tumors which were histologically benign. Acetone [4-(5-nitro-2-furyl)-2-thiazolyl]hydrazone induced multiple squamous papillomas of the nonglandular forestomach. 5-Nitro-2-furanmethandiol diacciate and l-[(5-nitrofurfurylidene)amino]hydantoin were inactive. These compounds were tested on the hypothesis that the 5-nitrofuran moiety might have carcinogenic activity. Since 2 of the nitrofurans were not carcinogenic, however, the possibility that the observed carcinogenic activity might have been due to the hydrazine or thiazole moieties also is discussed.